Dietary Supplement Intake, Folate and Vitamin B12 Status, and Cognitive Impairment Among Older Adults, National Health and Nutrition Examination Survey, 2011–2014

Abstract

ObjectivesCognitive decline is a major public health issue among older adults. Dietary supplement use is common among older adults, and a concern has been raised about high folic acid intake among those with vitamin B12 (vB12) deficiency and exacerbation of cognitive decline. We evaluated supplement intake and folate and vB12 concentrations among older adults with measured cognitive function. MethodsWe used NHANES 2011–2014 data on adults aged 60 + years (n = 3266) and estimated folic acid and vB12 intake from dietary supplements. We defined vB12 insufficiency as serum vB12 concentration ≤ 258 pmol/L and high folate concentrations as either serum folate ≥ 59 nmol/L or RBC folate ≥ 1609 nmol/L. Cognitive impairment was defined as a test score < 34 (< 25th percentile of the distribution) using the Digit Symbol Substitution Test. We adjusted for age, gender, ethnicity, marital status, education, poverty income ratio (PIR), and creatinine/albumin ratio in our analysis. We performed statistical analyses using weighted procedures in SAS-SUDAAN. ResultsOlder adults with cognitive impairment compared to those without were more likely to have less than a high school education; elevated serum methylmalonic acid; lower PIR; or to be non-Hispanic Black or Hispanic. Adults with cognitive decline were also less likely to use folic acid (29.2%) and vB12 (34.3%) supplements compared to those without cognitive decline (43.1% and 46.7%, respectively). Among vB12 insufficient adults, 18.0% were taking a vB12 supplement. After adjustment, compared to persons with normal folate and normal vB12 concentrations, persons with high folate and normal vB12 concentrations had a lower odds of having cognitive (adjusted OR [aOR]: 0.63; 95% confidence interval [CI]: 0.47, 0.85), and persons with high folate and insufficient vB12 concentrations had no significant difference in cognitive decline (aOR: 0.88; 95% CI: 0.36, 2.14). Among those who had cognitive decline with high folate and insufficient vB12 concentrations, 34.3% used a vB12 supplement. ConclusionsOur findings suggest that contrary to previous reports having concurrent high folate and insufficient vB12 concentrations was not associated with cognitive impairment. Adults who reported taking vB12 supplements orally and continue to have low vB12 concentrations may have vB12 malabsorption issues. Funding SourcesNA- CDC.